Hydrogen‐Bond Donor Passivation Coupled with Inductive Electronic Modulation Enables Highly Reversible Zn Anodes via Interfacial Microenvironment Engineering

Abstract In aqueous zinc‐ion batteries, suppressing the abnormal reactivity of water molecules at the zinc surface is a critical challenge for enhancing the stability of zinc anodes. Existing electrolyte additives can partially improve interfacial behavior. However, many of them contain strong hydrogen‐bonding (H‐bonding) donor groups that tend to form excessively strong H‐bonding with water molecules, which may inadvertently trigger overactivation of water and side reactions—a potential issue that has received limited systematic attention. Inspired by protein methylation, which regulates cellular phase separation by weakening H‐bonding, a functional electrolyte additive, N,N ‐dimethylnicotinamide (DMNA) is designed. The steric hindrance introduced by dual methyl substituents effectively weakens excessively strong H‐bonding between the amide group and water molecules, thereby preventing water overactivation‐induced side reactions. Simultaneously, the electron‐donating inductive (+I) effect increases the local electron density around the carbonyl oxygen, promoting directional coordination of Zn 2+ and accelerating the desolvation process, thus enabling efficient regulation of the interfacial microenvironment. Benefiting from this dual mechanism, Zn//Zn symmetric cells with DMNA exhibit a cycle life exceeding 8000 h at 0.5 mA cm −2 , and Zn//NH 4 V 4 O 10 pouch cells retain ≈100% capacity after 200 cycles. This study demonstrates that rational molecular design provides an effective approach for interfacial regulation.